US2770216A - Spraying apparatus for web material - Google Patents

Description

2 Shets-Sheet l A. SCHOCK SPRAYING APPARATUS FOR WEB MATERIAL Nov. 13, 1956 Filed Aug. 10, 1955 m v g A A A Nov. 13, 1956 A; SCHOCK SPRAYING APPARATUS FOR WEB MATERIAL Filed Aug. 10,- 1955 2 Sheets-Sheet 2 5 40 f t f 1 w INVENTQR ATTORNE United States Patent O SPRAYING APPARATUS FOR WEB MATERIAL Alfred Schock, Elmhurst, N. Y., assignor to Alexander Smith, Incorporated, Yonkers, N. Y., a corporation of New York Application August 10, 1955, Serial No. 527,467

2 Claims. (Cl. 118-323) This invention relates to an apparatus for spraying a material onto a moving surface, and more particularly to apparatus for applying material, such as adhesive or backsizing uniformly over a wide traveling web. The invention is particularly suited for use in the manufacture of broadloom carpets. It is suited however for use in i spraying material onto other types of webs or sheets where a substantially uniform spray over the e ir Width is essential.

In treating wide webs such as an 18 foot broadloom carpet it has been found that a single traversing nozzle is preferable to a bank of fixed nozzles because of the difficulty in maintaining absolute uniformity in a bank of individual nozzles and also because a single nozzle can be made to have a larger orifice which has many inherent advantages over a nozzle of smaller capacity. I

In order to ensure uniformity of treatment with a traversing nozzle, however, the nozzle should traverse at a rate to produce several spray overlaps on each part of the web so that each part of the Web is hit several times by the spray, thereby averaging out any non-irregularity in the spray fan. For an eighteen foot wide web traveling at a speed of twenty feet per minute and with a nozzle producing a two foot spray band, in order to make six overlaps the nozzle must make 67 passes per minute which would require a linear speed of travel of 1200 feet per minute. In addition the speed of traverse must be uniform at all times with a minimum time required for reversal.

For uniform spraying it is not necessary for the nozzle to travel in a straight line across the web. It may take an arcuate path or other non-linear path provided the rate of travel of the spray head is so selected that the transverse component of the rate of movement of the spray head remains constant.

In accordance with the present invention the spray head reciprocating means comprises an oscillatory lever which is pivotally mounted on a fixed support for reciprocation in a plane parallel to the plane of the web. The spray head is secured to one end of the lever. As the lever is oscillated the spray head is reciprocated back and forth across the web in an are about the lever pivot. The lever oscillating means is so constructed and arranged that the rate of the transverse component of the movement of the head across the web is substantially uniform whereby a substantially uniform coating is applied across the entire width of the web.

An object of the invention is to provide a simple and efficient apparatus for uniformly spraying a material onto a web or the like while it is being advanced at a constant rate.

Another object of the invention is to provide an apparatus of the aforesaid character in which a spray head is reciprocated back and forth transversely to a longitudinally advancing web by means of a lever which is oscillated by a driving means having the above characteristics.

Another object is to provide simple means for feeding 2,770,216 Patented Nov. 13, 1956 a plurality of material to a spray nozzle which is reciprocated at high speed.

Other and more specific objects of the invention will be apparent from the following description and theaccompanying drawings forming a part thereof in which:

Fig. 1 is a front elevation of a spraying apparatus embodying the invention with the air duct and drip collector removed for clarity;

Fig. 2 is a side elevation thereof looking from the right of Fig. 1;

Fig. 3 is an enlarged detail section taken on the line 3-3 of Fig. 2;

Fig. 4 is a diagrammatic view illustrating the manner of controlling the operation of the fluid-actuated operating piston;

Fig. 5 is a section taken on the line 55 of Fig. 6;

Fig. 6 is a horizontal section taken on the line 66 of Fig. 5; and

Fig. 7 is a vertical section taken on the line 7-7 of Fig. 1.

Referring now to the drawings by reference characters, a web 1 to be sprayed is drawn in a vertical path over longitudinally spaced fixed rollers 2 and 3. The web 1 is maintained taut between the rollers 2 and 3 and is advanced at a constant rate by suitable mechanism not shown. A spray head 4 is reciprocated back and forth from side to side across the web 1 along the are 5 by an oscillatory lever 6, which is pivotally mounted near one end thereof on a pin 7. The pin 7 is fixed on a support 8. The spray head 4 is rotatably mounted in a sleeve 11 which is secured to one end of the lever 6. The spraying material is supplied under pressure to the spray head 4 through the sleeve 11 by pipes 12 which are carried by the lever 6 and are connected near the pivot point 7 by flexible hoses to sources of supply of spray material. The pipes 12 may supply two different materials such as a coating material and a solvent or carrier for mixing in the head 4.

The spray head 4 is so constructed that it projects a narrow fan-shaped spray 15 against the web 1 as it is reciprocated back and forth across the advancing web. In order to reduce waste due to overspray, means are shown to maintain the spray fan 15 parallel with the axis of the advancing web. For this purpose the spray head 4 is provided with the oppositely extending arms 16 and a pair of similar arms are secured to the fixed pivot pin 7. The ends of the arms 16 are connected to the ends of the arms 17 by linking wires 18.

The oscillating means 14 for the lever 6 comprises a cylinder 19 and a fluid-actuated piston 20 which is movable back and forth in the cylinder 19 and has secured thereto a connecting rod 21 which extends out through both ends of the cylinder 10. The cylinder 19 is pivotally connected to the support 8 as indicated at 22, and one end of the connecting rod 21 is pivotally connected to the lever 6 as indicated at 23.

The lever arm from the point 23 to the pivot pin 7 is much shorter than the lever arm from the spray head 15 to the pin 7, for example with a ratio of 1:10, so that a comparatively short piston stroke causes the spray head to oscillate over a wide arc. Fluid under pressure is supplied to the cylinder 19 by a pump 24 through a fourway control valve 25 and the conduits 26 and 27. The direction of movement of the piston 20 is reversed after each oscillation of the lever 6 by any suitable means. As shown herein a pair of spaced fingers 30 and 31 are mounted on a rod 32 which is secured to the connecting rod 21 for movement therewith by the arms 33. As the piston 20 approaches the end of its movement in either direction the fingers 30 and 31 engage the lever 34 of the valve 25 and actuate the valve 25 to reverse the flow of fluid through the conduits 26 and 27.

An air duct 40 may be disposed opposite the spray path on the back of the web. This duct 40 is formed by a back wall 43, top wall 44, and bottom wall 45 forming an open channel member, closed at the front by the web itself.

Air under slight pressure is supplied to the duct 49 by a supply pipe 41 over a baflle 42 which directs the air along the duct to both sides of the web. This air current prevents overspray from drifting around the sides of the-web to the back thereof as the spray is being reversed. The open duct also projects beyond the web along the path of the spray to collect the overspray during reversal.

The duct may be provided with a drip pan 46 having a drain pipe 47 to collect and remove the overspray.

A spray drip collector 48 is shown as disposedover the front of the web extending below and along the arc of travel of the spray head and is provided with adischarge pipe 49 to collect and remove drip from the spray nozzle, particularly when the web is disposed in a vertical plane for spraying.

The rate of movement of the piston 20 from end toend of the cylinder 19 is constant in both directions. The horizontal component of the rate of travel of the spray head would be exactly constant, except for the slight variation produced by the pivotal movement of the cylinder 19 due to the arcuate path ofthe point 23.

The variation is reduced by making the distance from the connection point 23 to the pin 7 as short as possible andthe distance from the pin 7 to the pin 22 as long as possible. In the embodiment shown the variation in rate of travel is of the order of less than 1 percent.

Of course the transverse component of the nozzle speed could be made exactly constant by mounting the cylinder 19 in a fixed, horizontal position, and by allowing pin 7 to move in a vertical slot in support 8.

It will be noted that a uniform spray application is produced if the transverse (horizontal) component of the rate of the spray head across the web is constant as distinguished from a constant rate along the arc of travel. The present invention accordingly provides for-a uniform spray treatment with a high order of accuracy across even a wide web such asan eighteen foot broadloom carpet.

The hydraulic system provides for a constant rate of piston travel with a quick reversal at the ends of the path. For complete uniformity to the edges ofthe web the apparatus may be arranged for a slight overrun so that the reversal takes place when the spray head is beyond the edge of the web. The over-spray during reversal may be collected by a collecting pan if desired or the spray can be shut off during reversal.

Other reversing means such as limit switches or photoelectric relays actuating a four-way solenoid valve may be used. The lever 34 is shown as representative only.

Other drive means having uniform linear motion such as chain drives or cams may be used to reciprocate the lever.

The apparatus may be used for spray treatment of a broadloom carpet during the finishing operation or for applying a backsizing or foam to the carpet or for spray treating the pile or for painting wide webs or the like where a high degree of uniformity is required. By'a suitable construction of the parts a high linear speed of traverse can be obtained.

If the spray head is adapted to produce a cone of spray or if overspray is not objectionable, the mechanism for keeping the spray fan parallel to the edge of the web may be omitted.

A continuous web has been referred to for convenience. The term is intended to include a series of surfaces fed in sequence at a uniform rate past the spray are, such as panels or sheets on a conveyor.

It is to be understood that the invention is not limited to the specific construction shown and described herein as various modifications may be made therein Within the spirit of the invention and the scope of the appended claims.

What is claimed is:

1. An apparatus for spraying an advancing web, comprising a lever pivotally secured to a fixed support to oscillate in a plane parallel to said web, a spray head secured to the free end of said lever tobe oscillated thereby in an arcuate path across said web, means including a cylinder and afluid actuated piston connected to oscillate said lever, said piston being disposed to travel in .a path substantially transverse of said web whereby the transverse component of the'rate of traverse of said head is substantially proportional to the rate of traverseof said piston, an air duct disposed on the side of said web opposite said head, said duct comprising a channel member closed at the top by said web and projecting beyond said web at both sides. along the path of the spray to collect overspray duringreversal of movement-of said head, and means supplying air-under slight pressure to said duct to produce an air current at the sides of the web adapted to prevent drifting of 'overspray to the back of said web.

2. An apparatus for spraying an advancing web, comprising a lever pivotally secured to a .fixed support to oscillate in a plane parallel to said web, aspr'ay head secured .to the free end of said lever to be oscillated therebyin an arcuate path across said web, means including a cylinder and a fluid actuated piston, said piston beingdisposed to-travelin apath substantially transverse of said web whereby the transverse component of the rate of traverse ofsaid head is substantially proportional to the rate of traverse of said piston, an airduct disposed on the side of said web opposite-said head, said duct comprising a channel member closed at the top bysa-id web and projecting beyond said web at both sides 'alongithe path of the spray to collect overspray during reversal-0f movement of said head, means supplying air underslight pressure to said duct to produce an air j-current at fthexsides of the web adapted to prevent drifting of overspray to the back of said web, anda spraydripcollector disposed over the front of said web along and below the path-ofthe spray nozzle to collect and remove drip from said'nozzle.

References Cited in the file of this patent UNITED STATES PATENTS Szczepanski Nov. 30, 19.54

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